Mediators of Social Support and Antiretroviral Adherence Among an Indigent Population in New York City

Patients' adherence to long-term medications is influenced by many factors: characteristics of the patient, the patient-provider relationship, the illness or treatment regimen, and the context in which medical care is delivered. Nearly all HAART regimens produce significant side effects, some of which alter the quality of daily life. Self-efficacy refers to patients' beliefs about their capabilities and their ability to exercise personal control. Research has shown that patients who believe they will have trouble adhering to antiretroviral therapy often do have trouble, and that perceived self-efficacy is associated with greater medication adherence.

There is strong evidence that patients who suffer from anxiety and depression are less likely to adhere to a medication regimen. The presence of depressive symptomatology is one of the most consistent predictors of nonadherence among HIV-positive individuals.

Knowledge about HIV and HAART regimens may also influence adherence, the authors suggest. Previous studies and trials have indicated that patients with greater knowledge about HAART's effectiveness, and greater belief that poor adherence could promote viral resistance and treatment failure, have a greater ability to adhere to their medications. Less-adherent patients in HIV clinical trials were less sure of the link between nonadherence and the development of resistance.

The current study focuses on the role of social support in enhancing adherence. Factors thought to mediate the association between social support and adherence are self-efficacy, negative affective states, and knowledge of the medication regimen. For this study, a random sample of 50 primarily indigent, African-American and Puerto Rican men and women responded to survey interviews. The participants received treatment at an outpatient HIV clinic in the Bronx, New York.

The 31 women and 19 men interviewed for this study had a mean age of 41.45 years, and 70 percent had at least a high school education or GED. Eighty percent reported an income of less than $1,000 a month. Eighty-one percent classified their sexual orientation as exclusively heterosexual, ten percent as bisexual, and eight percent as homosexual. Twenty-four percent reported ever injecting drugs.

Analyses indicated that self-reported adherence was generally high. Medication adherence (percentage of prescribed medications taken in any form) and dose adherence (percentage of doses taken over doses prescribed) were both above 80 percent. However, more exacting adherence measures showed slightly lower levels: mean time adherence (taking each prescribed dose within two hours of when it was supposed to be taken) was 76 percent, mean pill adherence (percentage of medications for which the correct number of pills was taken at each dose) was 74 percent, and mean instructions adherence (percentage of medications for which the correct special instructions were followed at each dose) was 72 percent.

The intensity of side effects correlated with medication adherence, time adherence, dose adherence, and acknowledged nonadherence. "Forgot" (50 percent) and "felt worse" (46 percent) were the most common reasons given for nonadherence.

The need for social support was positively correlated with acknowledged nonadherence, although actual receipt of support was not. While the data do not establish a causal relationship, the results suggest that a lack of support from an affirming other, an information-enhancing relationship, an empathic listener, or a spiritual relationship can interfere with achieving greater adherence.

Analyses bore out that self-efficacy and depression can mediate the effect of the need for social support on nonadherence. Patients who think they can take their medication correctly usually show greater adherence outcomes, while depressed patients may have greater difficulty adhering to HAART regimens, possibly due to lack of physical and mental energy to keep up with the regimen, severe appetite changes that make it hard to follow special dietary instructions, and feelings of hopelessness. The authors did not find a significant correlation between adherence and medical knowledge, in contrast to their hypothesis.

The authors caution that self-reported adherence can overestimate true adherence rates. They suggest that future studies consider employing other potentially more valid measures such as an electronic monitoring device.

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